Membrane idealized

Ion-selective electrodes (ISEs) with ionophore-based membranes allow for quantification of a large number of analytes in various matrixes. Tailoring of the composition of the membranes to comply with the analytical task, requires advanced theory of membrane response. Most of theoretical descriptions include nonrealistic extra-thermodynamic assumptions, in the first place it is assumed that some kind of species strongly predominate in membranes. Ideally, a rigorous theory of ISE response should be based on strict thermodynamics. However, real ISE membranes are too complex. Therefore, known attempts aimed at rigorous thermodynamic description of ISEs proved to be fraritless. 

Well-mixed conditions at both sides. Constant effective diffusivities within the membrane. Ideal gas assumption. No pressure difference across the membrane. 

Production of high-purity water, concentration of food and heavy metal recovery from well water, river water, lake water, or industrial waste water Lower pressure brackish water membrane Ideal for small drinking water systems due to low energy consumption... 

The strength of the caustic produced in membrane cells depends on the type of membrane chosen. Since membranes ideally pass only water and alkali metal ions, chloride, chlorate, and sulfate in the caustic are measured in parts per million. The highest-grade caustic solutions (barring mercury contamination) are produced in amalgam cells. Through control of the rate of addition of water to the amalgam decomposer, these cells can also produce caustic directly at commercial concentrations (50% for NaOH and 45-50% for KOH). These differences result in the separate flow lines of Fig. 6.8. 

Gugliuzza A., Drioli E. (2007), PVDF and HYFLON AD membranes Ideal interfaces for contactor applications, J. Membrane 5 cf, 300,51-62. 

The membrane ideally should be of an inert material. However, because the chemical structure of the membrane might contribute to various interactions, the recovery of a certain analyte can vary with the membrane used. Table 9.8 lists some of the polymers used in microdialysis. 

The qualitative aspects of behavior of a pressurized bulge in a him are rendered most transparent when considered at the level of the membrane idealization. For example, for the most rudimentary membrane model depicted in Figure 5.32, it follows that the elastic strain energy for any given... 

Figure 2.3 Examples of permeate (y) versus feed mixture (x) composition curves, based on the membrane ideal selectivity (a ) eqn (2.12).

Gugliuzza, A. and E. Drioli. 2007. PVDF and HYFLON AD Membranes Ideal Interfaces for Contactor Applications. Journal of Membrane Science 300(1/2) 51-62. doi 10.1016/j. memsci.2007.05.004. 

Galvani potential at interface 1 or 2, respectively Ej) = possible diffusion potential within the membrane (idealized behavior) electrode potential with identical reference electrodes... 

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